The invention relates generally to powder actuated fastener setting tools, and more particularly to powder actuated fastener setting tools having an exhaust baffle and means for removing exhaust residue from the tool.
Powder actuated fastener setting tools are known and used widely, for example to fasten sill plates onto concrete slabs in the construction industry. U.S. Pat. No. 5,170,922 to Ehmig et al. discloses a tool comprising generally a barrel disposed reciprocatingly between extended and retracted positions in a receiver. The barrel is retractable in the receiver against the bias of a spring by depressing a muzzle thereof against a work piece to move a breech end of the barrel rearwardly toward a firing mechanism in a fire-ready position. The ignition of a propellant charge by the firing mechanism accelerates a piston through the barrel to set a fastener disposed previously in the muzzle thereof. The spring extends, or resets, the barrel in the receiver upon removal of the muzzle from the work piece. It is known to eliminate the spring member in other tools, particularly hand-held tools, and to reset the barrel manually, often by a throwing motion of the user's arm while holding the tool tightly.
In U.S. Pat. No. 5,170,922 to Ehmig et al., the piston is reset rearwardly toward the breech end of the barrel, for subsequent firing, by diverting a portion of the expanding gas from the discharged propellant toward the muzzle end of the barrel after setting the fastener. The rearwardly moving piston of Ehmig et al. expels the remaining expanded gas in the breech end of the barrel rearwardly and downwardly through channels that vent the gas from an underside of the tool near a hand-grip thereof. Other tools vent the gas from the muzzle end of the barrel after firing, and reset the piston by engaging a rearward end of the piston with one or more pawls extending through the barrel as the barrel is reset.
It is desirable generally to reduce or muffle noise generated by powder actuated fastener setting tools, particularly in hand-held tools operated in enclosed environments. Others have endeavored to address this problem. U.S. Pat. No. 3,743,048 to Bakoledis discloses, for example, a powder actuated fastener setting tool having a sound muffler disposed about a barrel thereof and coupled thereto by an o-ring. U.S. Pat. No. 4,196,834 to Beton discloses a fastener setting tool that vents gas radially outwardly from a rearward end of the barrel to an expansion chamber disposed thereabout where noise is suppressed, and then returns the gas from the expansion chamber back into the barrel at the muzzle end thereof. In U.S. Pat. No. 4,196,834 to Beton, the gas is ultimately discharged from the end of the barrel. U.S. Pat. No. 5,016,802 to Haytayan discloses a powder actuated setting tool that vents gas through radial ports at the muzzle end of a barrel and into a noise suppression element disposed thereabout. Other powder actuated fastener setting tools having sound suppression are disclosed in U.S. Pat. Nos. 3,743,048; 5,363,736 and 5,657,919.
The invention is drawn toward advancements in the art of powder actuated tools, and more particularly to novel tools that overcome problems in the art.
An object of the invention is to provide novel powder actuated fastener setting tools having one or more advantages over the prior art, including improved economy, improved reliability, spring assisted reset, improved noise suppression, improved recoil reduction, and improved exhaust residue removal, among other advantages disclosed further herein.
Another object of the invention is to provide novel powder actuated tools having a substantially enclosed exhaust baffle for baffling exhaust discharged from the tool during operation thereof.
A further object of the invention is to provide novel powder actuated tools having means for removing exhaust residue therefrom.
A more particular object of the invention is to provide novel powder actuated tools comprising generally a receiver for receiving a portion of a barrel that is reciprocatable therein between extended and retracted positions, and a substantially enclosed exhaust baffle disposed between the receiver and a muzzle of the barrel when the barrel is in the retracted position. In one embodiment, a cap including at least a cap end portion fixedly coupled axially to the muzzle and extending generally radially therefrom is matable with the receiver, or with a receiver sleeve extending from the receiver, when the barrel is in the retracted position to form the substantially enclosed exhaust baffle. In some embodiments, a cap sleeve extends from the cap end portion toward the receiver and is matable therewith, preferably overlapping a receiver sleeve thereof, to form the substantially enclosed exhaust baffle.
Another more particular object of the invention is to provide novel powder actuated tools comprising generally a spring member for biasing the barrel in the extended position upon removing the barrel from a work surface. The spring member may also act to connect the barrel to the remainder of the tool to increase the effective mass thereof and reduce recoil.
It is yet another more particular object of the invention to provide novel powder actuated tools comprising generally a spring member for removing exhaust residue from the powder actuated tool, particularly when the barrel of the tool is reciprocated between the extended and retracted positions.
These and other objects, aspects, features and advantages of the present invention will become more fully apparent upon careful consideration of the following Detailed Description of the Invention and the accompanying Drawings, which may be disproportionate for ease of understanding, wherein like structure and steps are referenced generally by corresponding numerals and indicators.